Turn-off for alternating-current circuits



(No Model.)

B. THOMSON.

TURN-OFF FOR ALTERNATING CURRENT, CIRCUITS. No. 428,647. -Patented May 27, 1890.

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UNITED STATES PATENT OFFICE.

ELIIIU THOMSON, OF LYNN, MASSACHUSETTS, ASSIGNOR TO THE THOMSON- I'IOUSTON ELECTRIC COMPANY, OF CONNECTICUT.

TURN-OFF FOR ALTERNATlNG-CURRENT CIRCUITS.

SPECIFICATION forming part of Letters Patent No. 428,647, dated May 27, 1890.

Application filed March 12, 1887. Serial No. 230,725. (No model.)

To all whom it may concern: when traversed by an alternating or varying Be it known that I, ELIHU THOMSON, a cit-icurrent. The coil maybe a sectional coil and zen of the United States, and a resident of be thrown into circuit in varying amounts Lynn, in the county of Essex and State of with its sections in series or in multiple to Massachusetts, have invented a certain new varythe counter kick orreaction. The switch and useful Turn-oil for Alternating-Current may cut the lamp or coil out by shunting or Circuits, of which the following is a specificabreaking the circuit of the same. tion. In the accompanying drawings, Figure l is My invention relates to a means for cona diagram illustrating my invention. Figs. IO trolling the action of an electric lamp or other 2 and 3 show modiiied forms of reactive coil. translating device operated by electric cur- Fig. 4 illustrates a construction of switch derents. vice that may be employed. Fig. 5 shows a My invention consists in the combination, modified arrangement of the reactive coil. with the translating device operated by alter- Referring to Fig. 1, m 01 indicate supply- 15 nating electric currents, of a reactive coil or mains leading from any source of alternating counter-electro-motive-forcc generator and an current-aster instance, from the secondary electric switch suitably constructed to throw of an induetion-coiland L L indicate the insaid generator into or out of circuit with the candescent lamps or other translating devices translating device, thereby changing the efto be connected in branch circuits between 20 fective currentthrough the same, and adapted the mains, so as to be traversed by the alterat its opposite extremes of movement, as herenating current. inafter described, to either permit the cur- R indicates a reactive coil, consisting in the rent to flow freely through the translating depresent instance of a coil of conducting-wire vice without opposition from the counterwhich is wrapped in a direction transverse to 2 5 electro-motive-force generator or to cut the its circumferential axis with iron wires or a current oit altogether from the translating magnetic envelope of any other desired form. device, while at the same time throwing the Aindicates the movable portion of a switch counter-elcctro-moiive-force generator out of of any suitable construction that moves over D Y a'series of contactflplat-es, the terminal one of 0 In the operation of the switch, as hereinwhich it is connected to one terminal of the after described, in one of its extreme posireactive coil. The other terminal of the retions the circuit will be opened, so as to cut active coil is connected to one of the mains, o'lf current both from the translating device while at intermediate points in the length of and reactivecoil. Atitsintermediate position said coil connections are taken in series to 5 the reactive device will be introduced into the contact-plates of the switch.- The switch operation in circuit with the lamp, and with arm A is connected to the lamp or other dea degree of reactive eitect depending upon the vice and through the same with the opposite extent of movement of the switch, while on main or. 9 continuation of the movement to the other At the end of the series of contact-plates of 40 extreme the reactive coil will be thrown out the switch opposite the end at which plate 70 of action altogether, leaving the current free is located is a contact-plate connected, as to flow through the translating device without shown, directly with the main m, so that when opposition. the switch A is on such contact current may Myinvention consists,als0, in the novel comflow directly from main m to the switch A and 4 5 bin ations and devices to be more particularly through the lamp to the opposite main n with specified in the claims. out passing through the reactive coil. The

In carrying out my invention I prefer to switch-arm A is also capable of being turned employ as the counter-electro-motive generinto the position indicated in the drawings, IOO atora reactive coil-that is to say, a coil which where it will be oft of any electric contact,

50 by being wound on an iron core or otherwise thereby opening the circuit through both the constructed has considerable magnetic reaclamp and the reactive coil. In the position tion and counter-electro-motive tendency of the arm shown the lamp and reactive c011 are out of circuit; but as the switch is moved to the left the lamp is introduced into circuit with the whole of the reactive coil and the amount of current aifecting the lamp or other translating device is cut down to an extent corresponding to the maximum reactive effect of which the coil is capable. As the switcharm moves to the left the number of the coilscctions in circuit is successively reduced until when the arm rests on the contact-plate at the opposite end of the series the coil is completely cut out and current flows to the lamp without obstruction from the reaction of the coils. The lamp L will then burn with its full brilliancy; but by turning the switch back to the right it may be caused to burn with less and less brillianey until finally it is put out entirely.

As before stated, a single coil might be employed and the switch constructed and arranged to throw the whole coil into and out of circuit with the lamp without any gradations of effect from the coil.

Fig. 2 illustrates a modified form of coil which is sometimes employed. In this case the condnoting-wires are wound 011 a ring of iron and connections made from the same to the switch-contacts in obvious manner.

The switch-arm A may be mounted in front of the reactive coil, and the whole then becomes a compact and simple turn-off switch, as seen in Fig. 3; butas there shown the middle point of contact leaves the reactive coil R out, and a movement either way puts in sections of R, and finally open -circuits both R and L.

The switch-arm A may be combined with a screw S, as indicated in Fig. 4, so as to secure a gradual movement of the switch.

In order to obtain a snap-like action of the switch in leaving the final contact, which opens the circuit, I employ a spring b, which is attached to or moves with the switch-arm A and the part making contact with the series of contact-plates, and provide at a a small projection, which obstructs the elastic arm Z) at the end of the movement of switch A, so that the arm I) will suddenly snap over and away from the final contact, when the force applied is suliicient to cause the spring I) to pass the projection. The projection a, being a part of the terminal contact-plate, and of conducting material, will obviously preserve the circuit until the very moment of rupture of connection, when the snapping action will take place. This would not be the case, obviously, if such stud or projection were of insulating material, since in such instance the rupture of circuit would be liable to take place before the spring would snap off of the stud.

I prefer to make the spring I) the circuitclosing portion, as indicated.

Fig. shows coil R arranged in sections in multiple, the switch-arm diminishing the reaction by putting more sections in multiple before shunting at D and taking them out successively before open-circuitin at F. The reaction may be given to the coils by any suitable construction, "as well understood in the art.

Any form of reactive coil 'or countercloctro-motive-force generator will answer the purposes of my invention.

lVhat I claim as my invention is 1. The combination, substantially as described, with a translating device supplied with alternating currents, of a switch A, adapted to be turned into open-circuit position, a reactive coil connected to a contact over which said switch may move, and a terminal contact placed at the opposite side of the first-named contact from that which the switch occupies when in open-circuit posi tion and connected to the circuit independently of the reactive coil,so as to permit current to flow through the switch and translating device without passing through the coil.

2. The combination of a translating device on an alternating-current circuit, a counterelectro-motive-force generator, and a circuitopening switch, all in series with one another, said switch having contacts connected to the counter-electro-motive-force generator and to a branch around the same, all as described, whereby the switch may in each of three positions respectively close the circuit through the translating device and counter-electromotive-force generator in series, close the circuit through the translating device independently of the countcr-electro-motive-force generator, and may break the circuit through both the translating device and the counterelectro-motive-foree generator.

The combination, substantially as described, with a translating device supplied with alternating currents, of a switch A, adapted to be turned into open-circuit position, a reactive coil having sections connected to aseries of contacts over which such switch may move, and a terminal contact placed at the end of the series where the reaction is least at the opposite extreme of movement of the switch to that which it occupies when in open-circuit position and connected to the circuit independently of the reactive coil, so as to permit current to flow through the switch and translating device without passing through the reactive coil, as and for the purpose described.

4. The combination, in an electric switch, of a spring-contact Z) and a terminal electric contact-stud a, arranged to obstruct the movement of the contact-stud b, so that the latter will by its resiliency snap away from the stud. Signed at Lynn, in the county of Essex and State of Massachusetts, this 7th day of March, A. D. 1887.

ELlllU TllOhlSQN.

Witnesses:

E. WILBUR RICE, J12, J. W. HBBONEY. 

